Binary star system in the constellation Orion
Nu Orionis (ν Orionis) is a binary star [ 11] system in the northeastern part of the constellation Orion . It should not be confused with the variable star NU Orionis .[ 12] Nu Orionis has an apparent visual magnitude of 4.42,[ 2] which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 0.00632 arcseconds ,[ 1] the distance to this system is roughly 520 light years .
This is a single-lined spectroscopic binary system,[ 9] which means that only the absorption line features of one of the components can be distinguished. The components orbit each other with a period of 131.2 days and an eccentricity of 0.64.[ 6] Depending on the source, the primary is either a B-type main sequence star with a stellar classification of B3 V,[ 3] or a more evolved B-type subgiant star of class B3 IV.[ 4] It has an angular diameter of 0.251 mas ,[ 13] which, at the estimated distance of this system, yields a physical size of about 4.3 times the radius of the Sun .[ 7] The mass is 6.7[ 4] times that of the Sun and it shines with 1,965[ 3] times the solar luminosity from its outer atmosphere at an effective temperature of 17,880 K.[ 8]
References
^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics , 474 (2): 653–664, arXiv :0708.1752 , Bibcode :2007A&A...474..653V , doi :10.1051/0004-6361:20078357 , S2CID 18759600 .
^ a b c d Crawford, D. L.; et al. (1971), "Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere", The Astronomical Journal , 76 : 1058, Bibcode :1971AJ.....76.1058C , doi :10.1086/111220 .
^ a b c d Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten , 331 (4): 349–360, arXiv :1003.2335 , Bibcode :2010AN....331..349H , doi :10.1002/asna.200911355 , S2CID 111387483 .
^ a b c d e Tetzlaff, N.; et al. (2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society , 410 (1): 190–200, arXiv :1007.4883 , Bibcode :2011MNRAS.410..190T , doi :10.1111/j.1365-2966.2010.17434.x , S2CID 118629873 .
^ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 , vol. 30, University of Toronto: International Astronomical Union , p. 57, Bibcode :1967IAUS...30...57E .
^ a b Pourbaix, D.; et al. (2004), "SB9 : The ninth catalogue of spectroscopic binary orbits", Astronomy and Astrophysics , 424 (2): 727–732, arXiv :astro-ph/0406573 , Bibcode :2004A&A...424..727P , doi :10.1051/0004-6361:20041213 , S2CID 119387088 .
^ a b Lang, Kenneth R. (2006), Astrophysical formulae , Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser , ISBN 3-540-29692-1 . . The radius (R* ) is given by:
2
⋅
R
∗
=
(
158.2
⋅
0.251
⋅
10
−
3
)
AU
0.0046491
AU
/
R
⨀
≈
8.5
⋅
R
⨀
{\displaystyle {\begin{aligned}2\cdot R_{*}&={\frac {(158.2\cdot 0.251\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 8.5\cdot R_{\bigodot }\end{aligned}}}
^ a b c d Gies, Douglas R.; Lambert, David L. (March 1992), "Carbon, nitrogen, and oxygen abundances in early B-type stars", Astrophysical Journal, Part 1 , 387 : 673–700, Bibcode :1992ApJ...387..673G , doi :10.1086/171116 .
^ a b Abt, Helmut A.; et al. (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal , 573 (1): 359–365, Bibcode :2002ApJ...573..359A , doi :10.1086/340590 .
^ "nu. Ori" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2016-11-03 .
^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society , 389 (2): 869–879, arXiv :0806.2878 , Bibcode :2008MNRAS.389..869E , doi :10.1111/j.1365-2966.2008.13596.x , S2CID 14878976 .
^ Marett-Crosby, Michael (2013), Twenty-Five Astronomical Observations That Changed the World: And How To Make Them Yourself , The Patrick Moore Practical Astronomy Series, Springer Science & Business Media, p. 93, ISBN 978-1461468004 .
^ Zorec, J.; et al. (July 2009), "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff ", Astronomy and Astrophysics , 501 (1): 297–320, arXiv :0903.5134 , Bibcode :2009A&A...501..297Z , doi :10.1051/0004-6361/200811147 , S2CID 14969137 .